What is natural attenuation?Natural attenuation makes use of natural processes to contain the spread of contamination from chemical spills and reduce the concentration and amount of pollutants at contaminated sites. Natural attenuation—also referred to as intrinsic remediation, bioattenuation, or intrinsic bioremediation—is an in situ treatment method. This means that environmental contaminants are left in place while natural attenuation works on them. Natural attenuation is often used as one part of a site cleanup that also includes the control or removal of the source of the contamination.

How does natural attenuation work? The processes contributing to natural attenuation are typically acting at many sites, but at varying rates and degrees of effectiveness, depending on the types of contaminants present, and the physical, chemical and biological characteristics of the soil and ground water. Natural attenuation processes are often categorized as destructive or non-destructive. Destructive processes destroy the contaminant. Non-destructive processes do not destroy the contaminant but cause a reduction in contaminant concentrations. Natural attenuation processes may reduce contaminant mass (through destructive processes such as biodegradation and chemical transformations); reduce contaminant concentrations (through simple dilution or dispersion); or bind contaminants to soil particles so the contamination does not spread or migrate very far (adsorption).

Biodegradation, also called bioremediation, is a process in which naturally occurring microorganisms (yeast, fungi, or bacteria) break down, or degrade, hazardous substances into less toxic or nontoxic sub-stances. Microorganisms, like humans, eat and digest organic substances for nutrition and energy. (In chemical terms, 'organic' compounds are those that contain carbon and hydrogen atoms.) Certain microorganisms can digest organic substances such as fuels or solvents that are hazardous to humans. Biodegradation can occur in the presence of oxygen (aerobic conditions) or without oxygen (anaerobic conditions). In most subsurface environments, both aerobic and anaerobic biodegradation of contaminants occur. The microorganisms break down the organic contaminants into harmless products-mainly carbon dioxide and water in the case of aerobic biodegradation.

Related articles

One of the main goals of every organic farmer is to build long-term soil fertility and tilth by feeding the soil with a variety of natural amendments. The regular addition of compost is one of the best ways to enhance the soil’s organic and humic content, which helps to build a fertile soil structure. This soil structure makes better use of water and nutrients. It is easier to till and, overall, is better able to achieve optimum yields on a long-term basis.
Since compost has already decomposed, its impacts...

What is Water RunOff?
Runoff is precipitation that did not get (infiltrated) absorbed into the soil, or did not evaporate, and therefore made its way from the ground surface into places that water collect. Runoff causes erosion, and also carry chemicals and substances on the ground surface along to the ponds,lakes and riverswhere the water ends up. (eschooltoday.com)
Phosphorus and Nitrogen in Water RunOff
Ponds and lakes are categorized by their total phosphorus level and high phosphorus waters are considered...

Nutrients (nitrogen and phosphorus) from agricultural non-point source (NPS) pollution have been increasingly recognized as a major contributor to the deterioration of water quality in recent years. The purpose of this article is to investigate the discrepancies in interception of nutrients in agricultural NPS pollution for eco-soil reactors using different filling schemes. Parallel eco-soil reactors of laboratory scale were created and filled with filter media, such as grit, zeolite, limestone, and gravel. Three...

The anaerobic process for the treatment of municipal and industrial wastewater has been in practice for over a century. Apart from treatment of wastewater, the process has the advantage of lower sludge and biogas production that can save energy. Application of this process in a primary clarifier in such a way that there is simultaneous digestion of primary settled sludge and organic removal from wastewater can be more advantageous in an aerobic treatment plant. The paper discusses the performance of such a...

As a representative species of nematodes, Caenorhabditis elegans is an attractive animal model for evaluating ecotoxicological effects and intrinsic mechanisms of stress response in vivo. To acquire a better knowledge of environmental effects of bisphenol A (BPA), ecotoxicological evaluations were conducted using C. elegans upon the physiological (growth, locomotion behaviors, and reproduction), biochemical (lipofuscin accumulation, reactive oxygen species production, and cell apoptosis), and molecular (stress‐rela...

Customer comments

No comments were found for A Citizen's Guide to Natural Attenuation. Be the first to comment!